{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,3]],"date-time":"2025-11-03T04:48:54Z","timestamp":1762145334939},"reference-count":0,"publisher":"American Physiological Society","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Cell Physiology"],"published-print":{"date-parts":[[1993,7,1]]},"abstract":"<jats:p> The ability of extracellular Ca2+ to refill internal Ca2+ stores of canine tracheal smooth muscle after a prior depletion by acetylcholine (ACh) was assessed using a novel sarcoplasmic reticulum (SR) Ca2+ pump inhibitor, cyclopiazonic acid (CPA). The transient contraction induced by ACh in a medium free of Ca2+ was used as an index for the content of agonist-sensitive intracellular Ca2+ stores. CPA inhibited in a concentration-dependent manner the refilling of the stores occurring during high KCl stimulation, and this inhibitory effect was independent of the external Ca2+ concentration. On the other hand, CPA was less effective in inhibiting the refilling occurring during prolonged ACh stimulation, especially when external Ca2+ concentration was raised. At 5.0 mM external Ca2+ or when 0.1 microM BAY 8644 was present in the medium, CPA was ineffective in inhibiting the refilling occurring during prolonged ACh stimulation. The maximum ACh-induced contraction in Ca(2+)-containing medium was independent of the extent of internal store Ca2+ load in the absence of L-type Ca2+ channel blocker but was highly dependent on the extent of internal Ca2+ load in the presence of the Ca2+ channel blocker. Hyperpolarization of the plasma membrane with the K+ channel opener cromakalim reduced the amplitude of ACh tonic contraction. Subsequent addition of nifedipine further reduced ACh tonic contraction. It is concluded that two different pathways for external Ca2+ are used to refill ACh-sensitive internal stores. One involves active Ca2+ uptake via a CPA-sensitive Ca2+ pump, and the other involves a CPA-insensitive pathway whose nature remains to be determined. <\/jats:p>","DOI":"10.1152\/ajpcell.1993.265.1.c28","type":"journal-article","created":{"date-parts":[[2017,12,24]],"date-time":"2017-12-24T14:52:11Z","timestamp":1514127131000},"page":"C28-C35","source":"Crossref","is-referenced-by-count":52,"title":["Distinct pathways to refill ACh-sensitive internal Ca2+ stores in canine airway smooth muscle"],"prefix":"10.1152","volume":"265","author":[{"given":"J. P.","family":"Bourreau","sequence":"first","affiliation":[{"name":"Department of Biomedical Sciences, McMaster University, Hamilton,Ontario, Canada."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C. Y.","family":"Kwan","sequence":"additional","affiliation":[{"name":"Department of Biomedical Sciences, McMaster University, Hamilton,Ontario, Canada."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E. E.","family":"Daniel","sequence":"additional","affiliation":[{"name":"Department of Biomedical Sciences, McMaster University, Hamilton,Ontario, Canada."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","container-title":["American Journal of Physiology-Cell Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.physiology.org\/doi\/pdf\/10.1152\/ajpcell.1993.265.1.C28","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,6,17]],"date-time":"2024-06-17T19:42:10Z","timestamp":1718653330000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.physiology.org\/doi\/10.1152\/ajpcell.1993.265.1.C28"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1993,7,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1993,7,1]]}},"alternative-id":["10.1152\/ajpcell.1993.265.1.C28"],"URL":"https:\/\/doi.org\/10.1152\/ajpcell.1993.265.1.c28","relation":{},"ISSN":["0363-6143","1522-1563"],"issn-type":[{"value":"0363-6143","type":"print"},{"value":"1522-1563","type":"electronic"}],"subject":[],"published":{"date-parts":[[1993,7,1]]}}}